Fuel cell systems are configured to supply power generated by a fuel cell to, for example, a household electrical load. The fuel cell in such a fuel cell system is interconnected with a commercial power system.
In such a fuel cell system, control is performed such that surplus power generated by the fuel cell does not flow into power of the power system. Specifically, there are known fuel cell systems in which surplus power generated by a fuel cell is consumed by an internal load (an electric heater) (see Patent Literatures 1 to 3, for example).
FIG. 4 is a block diagram schematically showing a schematic configuration of a fuel cell system disclosed in Patent Literature 1.
As shown in FIG. 4, the fuel cell system disclosed in Patent Literature 1 includes: a fuel cell 106 which is operated in a manner interconnecting with a commercial power system 167; an electric heater 153; and a heater controller 154. The fuel cell system is configured to supply surplus power generated by the fuel cell 106 to the electric heater 153. The heater controller 154 adjusts the amount of power supplied to the electric heater 153 by means of a switching element.    PTL 1: Japanese Laid-Open Patent Application Publication No. 2004-213985    PTL 2: Japanese Laid-Open Patent Application Publication No. 2001-68125    PTL 3: Japanese Laid-Open Patent Application Publication No. 60-117564